Electric switch



March 14, 1933.

L. HAAG ELECTRIC SWITCH Filed May 1, 1930 4 Sheets-Sheet l /NVE'NTOPKin/ aid 6 41.0%

March 14, 1933. L. HAAG 1,900,929

ELECTRIC SWITCH Filed May 1, 1930 4 Sheets-Sheet 2 3/ 2 ZQM March 14,1933. HAA 9 1,900,929

' ELECTRIC SWITCH Filed May 1, 1930 4 Sheets-Sheet 3 //VVEN 70/? March14, 1933. 1 HAAG 1,900,929

ELECTRIC SWITCH Filed May 1, 1950 4 Sheets-Sheet 4 #YVENTOR.

Maw" Patented Mar. 14, 1933 LEONHARD HAAG OF FRANKFOBT-ON-THE-MAIN,GERMANY ELECTRIC SWITCH Application filed Kay 1, 1930. Serial No.449,022.

This invention relates to excess current release devices so constructedthat they can be used for the releasing of various kmds of apparatus andcan be secured in position andexchanged in a simple manner.

An object of the invention is to provide a device of the characterdescribed in which a toothed wheel release mechanism normally locked bya fusible mass, of the smallest possible dimensions and heat consumptionmay be employed. Another object is to provide such a device with anelectromagnetic release acting immediately on the occurrence of suddenviolent surges such as short circuit currents and with means foradjusting the whole device to suit different operating conditions, asingle adjustment being effective both as regards the ratchet wheelrelease 'mechanism and the electromagnetic release. A further object isto provide a readily ad justable device which acts indirectly through amechanical energy store so that auxiliary contacts are avoided and sothat a small compact device is enabled to release relatively largeapparatus. A still further object of the invention is to provide astructure with simple regulating means in which the current at which theelectromagnetic release act and that at which, for a given time lag, thethermal-release acts are variable in common but in accordance withdifferent and independent functions of the exciting current.

With these objects in view, my invention comprises the combinationsdescribed below and pointed out in the ap ended claims.

In the accompanying rawings Figure 1 is an automatic switch furnishedwith two release devices constructed in accordance with the invention.

Figure 2 is a section on an enlarged scale on the line II-.II of Figure1, seen in the direction of the arrows.

Figure 3 shows how the same release devices as shown in Figures 1 and2,. can be ap lied to other apparatus.

igures 4 and 5 are two views at right angles to one another of thetransformer with the armature for effecting release on the occurrence ofheavy overloadsand the adj isting armature.

Figures 6 and 7 are corresponding views shplwmg the armatures in asecond position an Figures 8 and 9 are corresponding views showing thearmatures in a third position.

The details not necessary for following the arrangement of the armatureshave been omitted from Figures 4-9.

No detailed description of the switch shown in Figures 1 and 2 is givensince it is not in itself part of the invention and is not necessary forcomprehension thereof. The invention resides solely in the arrangementof the excess current release devices.

The release mechanism 4 comprising a toothed wheel normally locked by afusible mass, is secured on the iron core 2 of a current transformer bymeans of a mounting member 3. The windings of the transformer, of whichonly one is visible in the drawings since the second is covered by thefirst, are mounted on the middle limb of the core 2. The primary windingof the transformer is traversed by the current in the circuit to beprotected from overloads. The secondary winding is traversed by acurrent of small strength serving to heat the fusible mass of thereleasemechanism 4. Such release mechanisms are well known and adetailed description is there-fore unnecessary. They consist of atoothed wheel which is held stationary by the fusible mass which isheated by an electric current. When a current of relatively small excessvalue but of relatively long duration flows, the mass softens or meltsso that the wheel is released and can rotate under the influence of aforce. With the teeth of the wheel of the release mecha-. nism 4 meshesa member 5 by means of a small tooth like projection. The member 5 canhave several suchprojections and thus be in the form of a rack. It is'pivotally or yieldably secured to a plate 6 and displaceable againstspring pressure so that it can be moved out of engagement with the teethof" the wheel of the mechanism 4. Advantageously the memher 5 as shownin the drawings consist of a spring blade. The plate 6 which serves asthe release member is pivoted to a projection 7 on the core 2. Anot erprojection 8 on the core 2 serves for anchoring a helical springmagnetic field of the transformer. On the ture 13 which serves foradjusting t shaft 11 is also pivoted an adjustinlg armae magneticresistance of the transformer .core and thus for regulating the strengthof the secondary current which heats the fusible mass. To the 'core issecured a scale plate 14 which serves to indicate the adjustment of thearmature l3 and to which the latter can be clamped by a nut 16 on ascrew working in a slot 15 on the plate. To the plate 14 is secured oneend of a helical spring 17 the other end of which is secured to thearmature 12and tends to draw it away from the pole of the core 2 whichattracts it. The laminations of the armatures 12 and 13 are arranged instaggered relationship and intermesh one group with the other.

In Figures 4 and 5 the adjusting armature 13 is entered as far aspossible into the armature 12 so that the air gap 18 between them whichincreases the magnetic resistance is made as small as possible.

Figures 6 and 7 show a setting of the armature 13 in which the air gap18 is larger and the ratio of transformation therefore small- Figures 8and 9 show the largest air gap 18 obtainable by adjusting the armature13. By adjustment of the armature 13 not only is the magnetic resistancebetween itself and the armature 12 varied, but also that between itselfand the adjacent limb of the core 2.

If a relatively small but nevertheless excessive current flows, thearmature 12- will not be attracted with sufficient force to overcome thepull of the s ring 17 and the armature will not move.

the mechanism 4 will soften owing to the heating effect of the currentand the wheel will be free to rotate. Accordingly the part 6 can turnunder the influence of the spring 9. The rotation of the plate serve-sto release the locking deviceof the apparatus to which the releasingdevice is attached.

Upon a short circuit occurring damage might be done before the fusiblemass of the mechanism 4 had softened sufliciently. In this case therelease is effected by the armature 12 which is attracted by themagnetic force of the core sufliciently to overcome the force of thespring 17 and is immediately moved a ainst the member 5 which stands inits pat and thus moves the member 5 out n the other hand after the alapse of a certain time the fusible mass of of mesh with the wheelmechanism 4 so that the part 6 can rotate under'the action of the spring9 and release the locking device of the apparatus to which the device isattached.

The advantage of the invention lies in the simplicity of the mounting. Afew simple hand operations suffice to add the device all ready foroperation to a switch as shown in Figures 1 and 2. In the event ofdamage the release device can be immediately exchanged and the switchagain made ready for use. Since the release device isa constructionalunit it can be used in the most varied kinds of apparatus, as can begathered from Figure 3 where it is shown mounted on an insulator 19 andprovided with an operating rod 20 which conveys the releasing motion ofthe member 6 to the locking device of the apparatus in question.

What I claim is 1. In an indirect electric release device, thecombination of a magnetic core, an exciting wihding upon said core, arelease member movably mounted on said core, spring means for actuatingsaid release member anchored to said core, an armature pivoted to saidcore and under the influence of the magnetic field thereof, a secondarywinding upon said core, a release mechanism actuated by smallbutprotracted excess currents fed by said secondary winding and mounted onsaid core, a catch on said release member in the path of said armatureand normally held by said release mechanism, anadjusting armaturepivoted to said core for adjusting the ratio of transformation betweensaid exciting winding and said secondary winding, a projection on saidadjusting'armature lying in the magnetic circuit of said first mentionedarmature adapted to alter the reluctance thereof, a scale plate securedto said core, means for clamping said adjusting armature to saidscaleplate, and a spring connected between said scale plate and said firstmentioned armature tending to draw said first mentioned armature awayfrom said core.

2. In an indirect electric release device, the combination of an opencircuit magnetic core, an exciting winding upon said core, a

release member movably mounted on said core, spring means for actuatingsaid release member anchored to said core, an armature pivoted to saidcore forming a partial clo sure of said open circuit, a secondarywinding upon said core a release mechanism actuated by small butprotracted excess currents fed by said secondary winding and mounted onsaid core, a catch on said release member in the path of said armatureand normally held by said release mechanism, and an adjusting armaturefor regulating the ratio of transformation between said exciting windingand, said secondary winding, a projection on said adjusting armaturelying in the magnetic circuit of said first mentioned armature adaptedto alter the reluctance thereof.

3. In an indirect electric release device, the combination of a threelimbed open circuit magnetic core, a release member movably mounted onsaid core, an exciting winding on the center limb of said core, asecondary winding on the center limb of said core, spring means foractuating said release member anchored to said core, an armature foreffecting release on the occurrence of heavy overloads in said excitingwinding and an adjusting armature both pivoted to the center limb ofsaid core on a common shaft and extending in opposite directions towardsthe two outer limbs of said core respectively, said armaber anchored tosaid core,

. carried by tures also intermeshing in the neighborhood of said shaft,means for adjustably holding said adjusting armature, means urging saidfirst mentioned armature away from the respective outer limb of saidcore, a release mechanism actuated by small but protracted excesscurrents fed by said secondary winding and mounted on said core, and acatch on "said release member in the path of said first mentionedarmature and normally held by said release mechanism.

4. In an indirect electric release device, the combination of an opencircuit magnetic core, a release member pivoted to-said core, anexciting winding upon said core, a secondary winding linked by the wholeflux on said core, spring means for actuating said release memanarmature pivoted at one end to said core closing part of its opencircuit, an adjusting armature extending between said core and saidfirst mentioned armature, means for adjusting the gaps between the endsof said armatures and said core respectively, means urging said firstmentioned armature to swing out of the magnetic circuit, a releasemechanism actuated by small but protracted excess currents fed by saidsecondary winding and mounted on said core, and a catch on said releasemember in the path of said first mentioned armature and normally held bysaid release mecha- ,nism.

5. An indirect overload release device comprising a magnetic core, anexciting winding on said core, a secondary winding linked by the wholeflux on said core, a toothed Wheel release mechanism mounted on saidcore, a fusible mass normally locking said wheel mechanism and heated bythe output of said secondary winding, an armature pivoted to said coreand under the action of the magnetic field thereof, a movable releasemember said core, a blade spring on sai release'member in the path ofsaid armature and meshing with the wheel of said wheel mechanism, anadjusting armature pivoted to said core for adjustingthe ratio oftransformation between said exciting winding and said secondary winding,a projection on said adjusting armature lying in the magnetic circuit ofsaid first mentioned armature adapted to alter the reluctance thereof, ascale plate secured to said core, means for clamping said adjustingarmature to said scale plate, and a 'release mechanism mounted on saidcore, a

fusible mass normally locking said wheel mechanism and heated by theoutput of said secondary winding a movable release member carried bysaid core, a blade spring'on said release member meshing with the wheelof said wheel mechanism, means on'said core for disengaging said bladespring from said wheel on the occurrence of violent surges such as shortcircuit currents and a second arma ture pivoted tosaid core foradjusting the ratio of transformation between said exciting winding andsaid secondary winding, a projection on said adjusting armature lying inthe magnetic circuit of said first mentioned armature adapted to alterthe reluctance thereof.

7. An indirect overload release device comprising a magnetic core,anexciting winding upon said core, a secondary winding upon said core, atoothed wheel rotatably mounted on said core, a fusible mass normallylocking said wheel and heated by the output of said secondary winding, amovable release mem-' ber pivoted ,upon said core, spring means anchoredto said core for actuating sa d release member, a pawl on said releasemember normally meshing with said wheel whereby said release member andspring means are held out 'of action, an armature pivoted to said coreto complete the magnetic circuit thereof in such position as todisengage said pawl from said wheel when attracted by said core upon theflow of heavy overloads through said exciting winding, means opposingattraction of said armature, a second armature pivoted to said core foradjusting the ratio of transformation between said exciting wiuding andsaid secondary winding,

anchored to said core for actuating said release member, a blade springon sald release member, a pawl on said blade sprmg normally meshing withsaid wheel whereby said' release-member and said spring means are heldout of action, an armature pivoted to said core to complete the magneticcircuit thereof in such position as to move said blade spring and thusdisengage said pawl from said wheel when attracted by said core upon theflow of heavy overloads through said excitin winding, means opposingattraction of sai armature, a second armature pivoted to said core foradjusting the ratio of transformation between said exciting winding andsaid secondary winding and a projection on said second armature lylng inthe magnetic circuit of said first mentioned armature and adapted toalter the reluctance of said magnetic circuit. In testimony whereof Ihave signed my name to this specification.

LEON HARD HAAG.

